Messier 108

Messier 108 is one of the largest and brightest members of the Ursa Major galaxy cluster, which is part of the Virgo Supercluster.

Distance

46 million light-years

Apparent Magnitude

10.0

constellation

Ursa Major

object type

Barred Spiral Galaxy

Bright stars scatter across the field of view, more closely concentrated at the lower right. Dark brown lanes of dust spread throughout the view.
M108 is one of the largest and brightest members of the Ursa Major cluster, which is part of the Virgo Supercluster of galaxies. A portion of the galaxy is visible in this image.
NASA, ESA, and H. Bond (The Pennsylvania State University); Processing: Gladys Kober (NASA/Catholic University of America)

​M108, or the Surfboard galaxy, is located in the constellation Ursa Major approximately 46 million light-years away. It is called the Surfboard galaxy because, when viewed with a telescope, it is seen nearly edge-on with no apparent bulge or pronounced core.

M108 was discovered by Pierre Méchain in 1781 three days after he discovered M97. Charles Messier’s notes state that he observed the galaxy in 1781 but never took an accurate position of it or officially added it to his catalog. M108 was finally added to Messier’s catalog in 1953 by astronomer Owen Gingerich.

Pan-STARRS Image (lower left): A bright, nearly horizontal galaxy seen edge on against a black background. A the white square indicates the area of the galaxy in the Hubble image. Hubble Image (upper right): Bright stars scatter across the field of view, more closely concentrated at the lower right. Dark brown lanes of dust spread throughout the view.
A box in the ground-based, Pan-STARRS image of M108 at left shows the location of Hubble’s view on the right.
NASA, ESA, H. Bond (The Pennsylvania State University), and Pan-STARRS; Processing: Gladys Kober (NASA/Catholic University of America)

There is little evidence of a well-defined spiral pattern in the galaxy, but M108 is classified as a barred spiral galaxy with loosely wound spiral arms. Observations show young star clusters exposed against a mottled and detail-rich background. M108 also contains supershells, which are shells of gas driven by bursts of star formation and resulting supernova explosions. The supershells could also be driven by stellar jets or an infall of gas from outside the galaxy.

At the center of M108 is a supermassive black hole estimated to be 24 million times as massive as the Sun. The Chandra X-ray Observatory discovered multiple X-ray sources in M108, with the brightest X-ray source suspected to be an intermediately sized black hole that is actively accreting material.

Hubble image of M108
This Hubble image of M108 was taken using the Wide Field and Planetary Camera 2 and features only a portion of the galaxy. Its stair-step appearance results from the design of the camera, and because Hubble’s observations were taken in only one filter, it is in black and white. The observations were taken to help astronomers understand various features in the nuclei of nearby disk galaxies.
NASA, ESA, STScI and G. Illingworth (University of California, Santa Cruz)

M108 is one of the largest and brightest members of the Ursa Major cluster, which is part of the Virgo Supercluster of galaxies. It has a magnitude of 10 and is located just under the bowl of the Big Dipper. M108 can be seen with small telescopes as an elliptical streak of light with a brighter core, while telescopes 8 inches or larger will reveal more detail. The best time to observe M108 is in April, but it can be seen throughout the year for those in the Northern Hemisphere.

star chart showing location in night sky of M108
This star chart for M108 represents the view from mid-northern latitudes for the given month and time.
Image courtesy of Stellarium

Explore Hubble's Messier Catalog

The following pages contain some of Hubble’s best images of Messier objects.

Bright green, orange, and yellow tendrils intertwined within this egg shaped nebula.

Messier 1 (The Crab Nebula)

Better known as the Crab Nebula, Charles Messier originally mistook Messier 1 for Halley’s Comet, which inspired him to create…

A Hubble image of a ball of thousands of stars

Messier 2

Hubble's image of Messier 2 is comprised of visible and infrared wavelengths of light.

Hubble view of M3 - a ball of thousands of stars.

Messier 3

Messier 3 holds more than 500,000 stars.